HBsAg Test Positive: Introduction, Principle, Procedure and Result Interp

HBsAg Test Positive: Introduction, Principle, Procedure and Result Interpretation

Introduction of Hepatitis B virus

HBsAg test is positive as shown above picture. HBsAg stands for Hepatitis B surface antigen. HBsAg test is available in both rapid and ELISA methods but here we concern with the rapid HBsAg test. Hepatitis B virus (HBV) is a different virus from other hepatitis viruses like Hepatitis A, Hepatitis C, Hepatitis D, and Hepatitis E due to having DNA. It affects the liver and causing acute and chronic infection. The test kit is a product of J. MITRA & CO. PVT. LTD. named HEPACARD. It is a visual, rapid, sensitive, and accurate one-step immunoassay for the qualitative detection of Hepatitis B surface antigen in human serum or plasma. The test is intended to be used as an aid in the recognition and diagnosis of acute infections and chronic infections carriers of the Hepatitis B Virus(HBV).

Features of the test kit

Detects all the 11 subtypes of HBsAg.
Antigen Sensitivity: 0.5 ng/ml.
One-step single rapid immunoassay.
See-through Device for easy result interpretation
Shelf life: 18 months at 2-8°C.
100% Sensitivity and 100% Specificity by WHO Evaluation.
Test results can be read visually without any instrument.

Virus classification

Realm: Riboviria
Kingdom: Pararnavirae
Phylum: Artverviricota
Class: Revtraviricetes
Order: Blubervirales
Family: Hepadnaviridae
Genus: Orthohepadnavirus
Species: Hepatitis B virus

Mode of transmission

HBV is transmitted through exposure to infective blood, semen, and other body fluids. It can be transmitted from infected mothers to infants at the time of birth or from family member to infant in early childhood. Transmission may also occur through transfusions of HBV-contaminated blood and blood products, contaminated injections during medical procedures, and through injection drug use. It also poses a risk to healthcare workers who sustain accidental needle stick injuries while caring for infected-HBV patients. Safe and effective vaccines are available to prevent this HBV.

Prone to hepatitis B virus

Following groups are at particularly high risk of HBV infection and they are-

Healthcare workers (HCWs)
Men who have sex with other men
Persons who use IV drugs
People with multiple sex partners
Persons with chronic liver disease
People with renal disease
People over the age of 60 with diabetes mellitus
People, who are traveling to countries with a high incidence of HBV infection.

Symptoms of Hepatitis B infection

Symptoms of acute hepatitis B may not be visible for months. However, common symptoms are as follows-

Fatigue
Fever
Joint and muscle pain
Dark urine
Loss of appetite
Abdominal discomfort
Weakness
Yellowing of the whites of the eyes and skin

Lab Diagnosis of Hepatitis B virus

Hepatitis B surface antigen (HBsAg) test
Hepatitis B core antigen, or HBcAg test
Hepatitis B e antigen (HBeAg) test
Both IgM and IgG test
Viral load by PCR test

HBsAg test

Quick/ rapid/ spot test method

Principle

This is a qualitative test based on immunochromatographic techniques for the lateral association of antibodies specific for HBsAg.

Requirements for the test

The test kit contains-

Dropper
test cassettes or device
extra we need specimens i.e. serum/plasma

Test Procedure

Open cassette or device pouch.
Label it.
Put a drop of serum or plasma.
Wait for 15 minutes.

Observation

Observe the pink band.
Device A: one band at the control and another at the test region
Device B: Only on the band at the control region

Result and Interpretation

Only one band at control region: Test Negative
Two bands one at control region while another at test region: Test Positive
No band at all or band only at test region: Test Invalid
In this condition, repeat the test with another test device
Device A-Positive
Device B: Negative as shown above picture.

References

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4665901/
https://jmitra.tradeindia.com/hepacard-125721.html
http://www.biogatelab.com/hbsag-rapid-test.html
https://www.hepb.org/prevention-and-diagnosis/diagnosis/hbv-blood-tests/
https://www.healthline.com/health/hepatitis-b
https://en.wikipedia.org/wiki/Hepatitis_B_virus
https://www.who.int/news-room/fact-sheets/detail/hepatitis-b

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